This invention claims the benefit of U.S. patent application Ser. No. 10/088,941, Filed Mar. 21, 2002.
The invention relates to a windmill. A windmill of this type is known from DE 4402184. The known device discloses the general requirement of lubricating the main bearing. There is no disclosure of means to ensure that in the event of equipment failure, there remains sufficient oil in the bearing. To avoid this drawback, the windmill of the invention is designed to ensure that some lubrication remains in the main bearing in situations where the inflow of oil stops.
According to one embodiment of the invention, the windmill is designed to ensure that the proper functioning of the lubrication of the main bearing is monitored in an easy way.
According to another embodiment of the invention, the windmill is designed to ensure that failure of the lubrication system can be detected at an early stage and damage to the main bearing can be prevented.
Further description of the invention is incorporated by reference from publication WO 0121956, page 2 line 13 to page 11 line 35, and figures according to FIGS. 1–9 of WO 0121956.
The invention relates to a windmill according to the preamble of claim 1. A windmill of this type is known from DE 4402184. In the known device, it is possible that moisture may be deposited on the windings of the generator while the windmill is at a standstill. In this case, before the windmill can be started up, the stator has to be heated in order to expel the moisture, since otherwise a short circuit may occur in the windings of the stator. This heating takes up considerable time, which consequently has an adverse effect on the time for which the windmill can be used to good effect. To avoid this drawback, the device is designed in accordance with the preamble of claim 1. This prevents moist air from being fed into the chamber around the stator, thus avoiding the deposition of moisture.
According to a refinement, the invention is designed in accordance with claim 2. This further reduces the risk of condensation on the stator.
According to a refinement, the device is designed in accordance with claim 3. This prevents moist air from being fed into the closed chamber.
According to a refinement, the device is designed in accordance with claim 4. As a result, the air is dried only when there is a risk of condensation, so that the wear to the air dryer is limited.
According to a refinement, the device is designed in accordance with claim 5. This ensures that the stator is at a uniform temperature all the way around and there is no possibility of local condensation. The stator is also prevented from becoming unwound, so that the air gap can be kept smaller.
According to one embodiment, the windmill is designed in according with claim 6. As a result, it is impossible for any air to be supplied or discharged along the bearing and, if appropriate, a superatmospheric pressure may be applied in the closed chamber.
According to one embodiment, the windmill is designed in accordance with claim 7. This makes it easier to check the presence of lubricant in the bearing, so that there is no damage caused to the seals as a result of absence of lubricant.
According to a refinement, the device is designed in accordance with claim 8. As a result, it is easily possible to check on an ongoing basis that the bearing and the seals are being lubricated correctly and, if necessary, to institute appropriate measures.